- Introduction to Anatomy
- Primary Tissues
- Special Connective Tissues
- Nervous Tissues
- Muscle Tissues
- Lymphoid Tissues
- Skin and its Appendages
- ▪ Introduction
- ▪ Medical and Anatomical Terminology
- • The Anatomical Position
- • The Anatomical Planes
- ▪ Terms
- • Terms of Relationship
- • Terms of Movement
- • The Meaning of Terms
- ▪ Approaches in Studying Anatomy
- • Regional Anatomy or Topographical Anatomy
- • Systemic Anatomy
- • Clinical Anatomy
- • Gross Anatomy and Histology
- • Anatomical Variations
Anatomy is the study of structure and function of the body. Aristotle (384–322 BC) was the first person to use the term “anatome”, a Greek word meaning “cutting up or taking apart”. The Latin word “dissecare” has a similar meaning.
Anatomy is one of the oldest basic medical sciences; it was first studied formally in Egypt. Human Anatomy was taught in Greece by Hippocrates (460–377 BC) who is regarded as the “Father of Medicine”. He has written several books on Anatomy.
MEDICAL AND ANATOMICAL TERMINOLOGY
Although students entering the new world of Medicine are familiar with the common terms for many parts and regions of the body (e.g. heart, brain, liver, lung), they should learn to use the internationally adopted nomenclature, the Nomina Anatomica.
Anatomical terminology is important because it introduces the student to a large part of Medical Terminology. Since most terms are derived from Latin and Greek, medical language can be difficult at first, but as the student learns the origin of medical terms, the words make sense.
Example: Levator palpebrae superioris muscle
Clear communication is fundamental in Clinical Medicine. To describe the body clearly and to indicate the position of its parts and organs relative to each other, Anatomists and Clinicians use the same descriptive terms of position and direction.
The Anatomical Position (Fig. 1.1)
All descriptions in Human Anatomy and Clinical Medicine are expressed in relation to “Anatomical Position”.
A person in the anatomical position is standing erect (or lying supine) with the head, eyes and toes directed forward, the upper limbs by the sides with the palms facing anteriorly. The student must always visualize the anatomical position in his “mind's eye” when describing patients lying on their backs, sides or fronts. Always describe the body as if it were in the anatomical position.
The Anatomical Planes
Anatomical descriptions are also based on four imaginary planes that pass through the body in the anatomical position. They are as follows:
The Median Plane (Fig. 1.2)
This is the imaginary vertical plane passing longitudinally through the body from front to back, dividing it into right and left halves.
The Sagittal Planes
These are parallel to the median plane. They are named after the sagittal suture of the skull (Fig. 1.3). The sagittal plane that passes through the median plane can be called the midsagittal plane; those passing parallel to the midsagittal plane and away from the median plane may be called the parasagittal planes.
The Coronal Planes
These are imaginary vertical planes passing through the body at right angles to the median plane, dividing it into anterior (front) and posterior (back) portions. These planes are named after the coronal suture of the skull, which is in a coronal plane (Fig. 1.3).
The Horizontal Planes
These are imaginary planes passing through the body at right angles to both the median and coronal planes (They are parallel to the “horizon”). A horizontal plane divides the body into superior (upper) and inferior (lower) parts. A horizontal plane is also referred to as the transverse plane (Fig. 1.4).
Terms of Relationship (Table 1.1)
Various terms (adjectives) are used to describe the relationship of parts of the body in the Anatomical Position.
Various terms are used to describe the different movements of the limbs and other parts of the body. Movements take place at joints where two or more bones meet or articulate with one another.
The Meaning of Terms
Most of the anatomical terms are derived from Greek and Latin. Some of them are translated to English (e.g. musculus = muscle). Many anatomical terms indicate the shape, size, location and function or resemblance of a structure to something.
- According to shape
- Deltoid – delta or triangular
- Sphenoid – wedge-shaped
- Styloid – pillar-shaped
- Uvula – grape-like
- Pisiform – Pea-shaped
- According to the number of heads of origin
- Biceps – 2 heads
- Triceps – 3 heads
- Quadriceps – 4 heads
- According to functionFor example,
- Depressor anguli oris – Muscle which depresses the angle of mouth
- Tensor tympani – Muscle which tenses the tympanic membrane
- According to size
- Gluteus maximus – Largest among the gluteus muscles
- Gluteus minimus – Smallest among the gluteus muscles
- According to length
- Abductor pollicis longus – Long abductor of thumb
- Abductor pollicis brevis – Short abductor of thumb
- According to consistency
- Pancreas – Pan = throughout; Kreas = Flesh; fleshy throughout
- Dura mater – Dura = tough; Mater = mother; Tough mother
- According to location
- Biceps brachii – Biceps muscle of arm
- Biceps femoris – Biceps muscle of thigh
- Triceps suri – 3 muscles of calf
- According to sites of attachmentFor example,
- Sternocleidomastoid muscle – attached to sternum, clavicle and mastoid
- Omohyoid; omos = shoulder
Omohyoid – from scapula (shoulder blade) to hyoid.
Some of the commonly used anatomical and clinical abbreviations are given in Table 1.3.
APPROACHES IN STUDYING ANATOMY
The three main approaches are as follows:
- Regional Anatomy
- Systemic Anatomy
- Clinical Anatomy
Regional Anatomy or Topographical Anatomy
It is the study of the body by regions such as head, neck, thorax, abdomen and limbs.
Systemic Anatomy (Table 1.4)
Correlation of anatomy with clinical signs and symptoms to arrive at a diagnosis.
Gross Anatomy and Histology
It is the examination of body structures that can be seen without a microscope.
Microscopic study of a tissue.
Individuals differ in physical appearance. Similarly variations are seen in the size, shape, weight, origin, course and termination of various organs, arteries, nerves and veins. So, individual variation must be considered while examining a patient and in the diagnosis and treatment of that patient.